Definition of "punkin"

When the frost is on the punkin and the fodder's in the shock […]

1911, James Whitcomb Riley, When the Frost is on the Punkin

There was some laughter, and Roddle was left free to expand his ideas on the periodic visits of cowboys to the town. “Mason Rickets, he had ten big punkins a-sittin' in front of his store, an' them fellers from the Upside-down-F ranch shot 'em up […].”

1899, Stephen Crane, chapter 1, in Twelve O'Clock